Childhood socio-economic position and risk of coronary heart disease in middle age: a study of 49 321 male conscripts

Background: Poor social circumstances in childhood are associated with increased risk of coronary heart disease (CHD). In previous studies, social circumstances and risk factors in adulthood have been suggested to explain this association. In the present study, we included potential explanatory factors from childhood and adolescence. Methods: We investigated the association between childhood socio-economic position (SEP) and CHD in middle age among 49 321 Swedish males, born during 1949–51, who were conscripted for military service at 18–20 years of age. Register-based data on childhood social circumstances, educational attainment and occupational class in adulthood were used in combination with information on cognitive ability, smoking, body mass index and body height in late adolescence obtained from a compulsory conscription examination. Incidence of CHD from 1991 to 2007 (between 40 and 58 years of age) was followed in national registers. Results: We demonstrated an inverse association between childhood SEP and CHD in middle age: among men with the lowest childhood SEP the crude hazard ratio of CHD was 1.47 (95% CI = 1.30–1.67). Adjustment for crowded housing in childhood, body height, cognitive ability, smoking and BMI in late adolescence attenuated relative risks of CHD considerably. Additional adjustment for educational level had a further, although limited, attenuating effect on associations, but additional adjustment for occupational class had no such effect. Conclusions: Results showed that social, cognitive and behavioural factors evident prior to adulthood may be of greater importance in explaining the association between childhood SEP and CHD later in life than socio-economic indicators in adulthood.

Prenatal and childhood growth and leisure time physical activity in adult life

Background: Physical activity plays an important role in prevention of chronic diseases. Animal studies have suggested that lifestyle and exercise habits may have a prenatal origin. Our aim was to assess the role of early growth on leisure time physical activity (LTPA) in later life among 57–70-years-old men and women. Methods: We examined 2003 individuals born in Helsinki, Finland between 1934 and 1944. Of them, 1967 individuals with adequate information on their LTPA in adult life were included in this study. LTPA was assessed by a validated exercise questionnaire (KIHD Study 12 month physical activity history). Subjects’ birth and serial growth measurements were obtained from birth, child welfare and school health records. Results: Participants with higher engagement in LTPA showed a more favourable adult anthropometric and body composition profile than those who were less active. LTPA was positively associated with adult social class. Higher weight and length at birth, and weight at 2 years after adult BMI adjustment, predicted higher intensity of total LTPA (P = 0.04, P = 0.01 and P = 0.03), respectively. Higher height at 2, 7 and 11 years predicted higher intensity of conditioning LTPA (P = 0.01, P = 0.04 and P = 0.004). Higher weight and height at 2, 7 and 11 years predicted higher energy expenditure (EE) of total LTPA (P-values being from 0.01 to 0.03). Furthermore, higher height at 2 and 11 years predicted higher EE of conditioning LTPA (P = 0.02 and P = 0.03). Conclusion: People who as children were taller and weighed more engage more in leisure time physical activity in late adulthood.